import re
from time import sleep

import pytest
import requests
from fastapi import FastAPI

from pyinfra.webserver.prometheus import (
    add_prometheus_endpoint,
    make_prometheus_processing_time_decorator_from_settings,
)
from pyinfra.webserver.utils import create_webserver_thread_from_settings


@pytest.fixture(scope="class")
def app_with_prometheus_endpoint(settings):
    app = FastAPI()
    app = add_prometheus_endpoint(app)
    thread = create_webserver_thread_from_settings(app, settings)
    thread.daemon = True
    thread.start()
    sleep(1)
    yield
    thread.join(timeout=1)


@pytest.fixture
def monitored_function(settings):
    @make_prometheus_processing_time_decorator_from_settings(settings)
    def process(*args, **kwargs):
        sleep(0.5)

    return process


class TestPrometheusMonitor:
    def test_prometheus_endpoint_is_available(self, app_with_prometheus_endpoint, settings):
        resp = requests.get(f"http://{settings.webserver.host}:{settings.webserver.port}/prometheus")
        assert resp.status_code == 200

    def test_processing_with_a_monitored_fn_increases_parameter_counter(
        self, app_with_prometheus_endpoint, monitored_function, settings
    ):
        pattern = re.compile(rf".*{settings.metrics.prometheus.prefix}_processing_time_count (\d\.\d).*")

        resp = requests.get(f"http://{settings.webserver.host}:{settings.webserver.port}/prometheus")
        assert pattern.search(resp.text).group(1) == "0.0"

        monitored_function()
        resp = requests.get(f"http://{settings.webserver.host}:{settings.webserver.port}/prometheus")
        assert pattern.search(resp.text).group(1) == "1.0"

        monitored_function()
        resp = requests.get(f"http://{settings.webserver.host}:{settings.webserver.port}/prometheus")
        assert pattern.search(resp.text).group(1) == "2.0"